node: refactor package node (#21105)

This PR significantly changes the APIs for instantiating Ethereum nodes in
a Go program. The new APIs are not backwards-compatible, but we feel that
this is made up for by the much simpler way of registering services on
node.Node. You can find more information and rationale in the design
document: https://gist.github.com/renaynay/5bec2de19fde66f4d04c535fd24f0775.

There is also a new feature in Node's Go API: it is now possible to
register arbitrary handlers on the user-facing HTTP server. In geth, this
facility is used to enable GraphQL.

There is a single minor change relevant for geth users in this PR: The
GraphQL API is no longer available separately from the JSON-RPC HTTP
server. If you want GraphQL, you need to enable it using the
./geth --http --graphql flag combination.

The --graphql.port and --graphql.addr flags are no longer available.

Author: renaynay

cmd/faucet/faucet.go

@@ -235,23 +235,20 @@ func newFaucet(genesis *core.Genesis, port int, enodes []*discv5.Node, network u
 	if err != nil {
 		return nil, err
 	}
+
 	// Assemble the Ethereum light client protocol
-	if err := stack.Register(func(ctx *node.ServiceContext) (node.Service, error) {
-		cfg := eth.DefaultConfig
-		cfg.SyncMode = downloader.LightSync
-		cfg.NetworkId = network
-		cfg.Genesis = genesis
-		return les.New(ctx, &cfg)
-	}); err != nil {
-		return nil, err
+	cfg := eth.DefaultConfig
+	cfg.SyncMode = downloader.LightSync
+	cfg.NetworkId = network
+	cfg.Genesis = genesis
+	lesBackend, err := les.New(stack, &cfg)
+	if err != nil {
+		return nil, fmt.Errorf("Failed to register the Ethereum service: %w", err)
 	}
+
 	// Assemble the ethstats monitoring and reporting service'
 	if stats != "" {
-		if err := stack.Register(func(ctx *node.ServiceContext) (node.Service, error) {
-			var serv *les.LightEthereum
-			ctx.Service(&serv)
-			return ethstats.New(stats, nil, serv)
-		}); err != nil {
+		if err := ethstats.New(stack, lesBackend.ApiBackend, lesBackend.Engine(), stats); err != nil {
 			return nil, err
 		}
 	}
@@ -268,7 +265,7 @@ func newFaucet(genesis *core.Genesis, port int, enodes []*discv5.Node, network u
 	// Attach to the client and retrieve and interesting metadatas
 	api, err := stack.Attach()
 	if err != nil {
-		stack.Stop()
+		stack.Close()
 		return nil, err
 	}
 	client := ethclient.NewClient(api)

cmd/geth/chaincmd.go

@@ -239,8 +239,9 @@ func initGenesis(ctx *cli.Context) error {
 	if err := json.NewDecoder(file).Decode(genesis); err != nil {
 		utils.Fatalf("invalid genesis file: %v", err)
 	}
+
 	// Open an initialise both full and light databases
-	stack := makeFullNode(ctx)
+	stack, _ := makeConfigNode(ctx)
 	defer stack.Close()
 
 	for _, name := range []string{"chaindata", "lightchaindata"} {
@@ -277,7 +278,7 @@ func importChain(ctx *cli.Context) error {
 	utils.SetupMetrics(ctx)
 	// Start system runtime metrics collection
 	go metrics.CollectProcessMetrics(3 * time.Second)
-	stack := makeFullNode(ctx)
+	stack, _ := makeFullNode(ctx)
 	defer stack.Close()
 
 	chain, db := utils.MakeChain(ctx, stack, false)
@@ -371,7 +372,7 @@ func exportChain(ctx *cli.Context) error {
 	if len(ctx.Args()) < 1 {
 		utils.Fatalf("This command requires an argument.")
 	}
-	stack := makeFullNode(ctx)
+	stack, _ := makeFullNode(ctx)
 	defer stack.Close()
 
 	chain, _ := utils.MakeChain(ctx, stack, true)
@@ -406,7 +407,7 @@ func importPreimages(ctx *cli.Context) error {
 	if len(ctx.Args()) < 1 {
 		utils.Fatalf("This command requires an argument.")
 	}
-	stack := makeFullNode(ctx)
+	stack, _ := makeFullNode(ctx)
 	defer stack.Close()
 
 	db := utils.MakeChainDatabase(ctx, stack)
@@ -424,7 +425,7 @@ func exportPreimages(ctx *cli.Context) error {
 	if len(ctx.Args()) < 1 {
 		utils.Fatalf("This command requires an argument.")
 	}
-	stack := makeFullNode(ctx)
+	stack, _ := makeFullNode(ctx)
 	defer stack.Close()
 
 	db := utils.MakeChainDatabase(ctx, stack)
@@ -446,7 +447,7 @@ func copyDb(ctx *cli.Context) error {
 		utils.Fatalf("Source ancient chain directory path argument missing")
 	}
 	// Initialize a new chain for the running node to sync into
-	stack := makeFullNode(ctx)
+	stack, _ := makeFullNode(ctx)
 	defer stack.Close()
 
 	chain, chainDb := utils.MakeChain(ctx, stack, false)
@@ -554,7 +555,7 @@ func confirmAndRemoveDB(database string, kind string) {
 }
 
 func dump(ctx *cli.Context) error {
-	stack := makeFullNode(ctx)
+	stack, _ := makeFullNode(ctx)
 	defer stack.Close()
 
 	chain, chainDb := utils.MakeChain(ctx, stack, true)

cmd/geth/config.go

@@ -28,6 +28,7 @@ import (
 
 	"github.com/ethereum/go-ethereum/cmd/utils"
 	"github.com/ethereum/go-ethereum/eth"
+	"github.com/ethereum/go-ethereum/internal/ethapi"
 	"github.com/ethereum/go-ethereum/node"
 	"github.com/ethereum/go-ethereum/params"
 	whisper "github.com/ethereum/go-ethereum/whisper/whisperv6"
@@ -144,9 +145,10 @@ func enableWhisper(ctx *cli.Context) bool {
 	return false
 }
 
-func makeFullNode(ctx *cli.Context) *node.Node {
+func makeFullNode(ctx *cli.Context) (*node.Node, ethapi.Backend) {
 	stack, cfg := makeConfigNode(ctx)
-	utils.RegisterEthService(stack, &cfg.Eth)
+
+	backend := utils.RegisterEthService(stack, &cfg.Eth)
 
 	// Whisper must be explicitly enabled by specifying at least 1 whisper flag or in dev mode
 	shhEnabled := enableWhisper(ctx)
@@ -165,13 +167,13 @@ func makeFullNode(ctx *cli.Context) *node.Node {
 	}
 	// Configure GraphQL if requested
 	if ctx.GlobalIsSet(utils.GraphQLEnabledFlag.Name) {
-		utils.RegisterGraphQLService(stack, cfg.Node.GraphQLEndpoint(), cfg.Node.GraphQLCors, cfg.Node.GraphQLVirtualHosts, cfg.Node.HTTPTimeouts)
+		utils.RegisterGraphQLService(stack, backend, cfg.Node)
 	}
 	// Add the Ethereum Stats daemon if requested.
 	if cfg.Ethstats.URL != "" {
-		utils.RegisterEthStatsService(stack, cfg.Ethstats.URL)
+		utils.RegisterEthStatsService(stack, backend, cfg.Ethstats.URL)
 	}
-	return stack
+	return stack, backend
 }
 
 // dumpConfig is the dumpconfig command.

cmd/geth/consolecmd.go

@@ -78,12 +78,12 @@ JavaScript API. See https://github.com/ethereum/go-ethereum/wiki/JavaScript-Cons
 func localConsole(ctx *cli.Context) error {
 	// Create and start the node based on the CLI flags
 	prepare(ctx)
-	node := makeFullNode(ctx)
-	startNode(ctx, node)
-	defer node.Close()
+	stack, backend := makeFullNode(ctx)
+	startNode(ctx, stack, backend)
+	defer stack.Close()
 
 	// Attach to the newly started node and start the JavaScript console
-	client, err := node.Attach()
+	client, err := stack.Attach()
 	if err != nil {
 		utils.Fatalf("Failed to attach to the inproc geth: %v", err)
 	}
@@ -190,12 +190,12 @@ func dialRPC(endpoint string) (*rpc.Client, error) {
 // everything down.
 func ephemeralConsole(ctx *cli.Context) error {
 	// Create and start the node based on the CLI flags
-	node := makeFullNode(ctx)
-	startNode(ctx, node)
-	defer node.Close()
+	stack, backend := makeFullNode(ctx)
+	startNode(ctx, stack, backend)
+	defer stack.Close()
 
 	// Attach to the newly started node and start the JavaScript console
-	client, err := node.Attach()
+	client, err := stack.Attach()
 	if err != nil {
 		utils.Fatalf("Failed to attach to the inproc geth: %v", err)
 	}

cmd/geth/dao_test.go

@@ -119,8 +119,7 @@ func testDAOForkBlockNewChain(t *testing.T, test int, genesis string, expectBloc
 	} else {
 		// Force chain initialization
 		args := []string{"--port", "0", "--maxpeers", "0", "--nodiscover", "--nat", "none", "--ipcdisable", "--datadir", datadir}
-		geth := runGeth(t, append(args, []string{"--exec", "2+2", "console"}...)...)
-		geth.WaitExit()
+		runGeth(t, append(args, []string{"--exec", "2+2", "console"}...)...).WaitExit()
 	}
 	// Retrieve the DAO config flag from the database
 	path := filepath.Join(datadir, "geth", "chaindata")

cmd/geth/main.go

@@ -36,8 +36,8 @@ import (
 	"github.com/ethereum/go-ethereum/eth/downloader"
 	"github.com/ethereum/go-ethereum/ethclient"
 	"github.com/ethereum/go-ethereum/internal/debug"
+	"github.com/ethereum/go-ethereum/internal/ethapi"
 	"github.com/ethereum/go-ethereum/internal/flags"
-	"github.com/ethereum/go-ethereum/les"
 	"github.com/ethereum/go-ethereum/log"
 	"github.com/ethereum/go-ethereum/metrics"
 	"github.com/ethereum/go-ethereum/node"
@@ -171,8 +171,6 @@ var (
 		utils.LegacyRPCCORSDomainFlag,
 		utils.LegacyRPCVirtualHostsFlag,
 		utils.GraphQLEnabledFlag,
-		utils.GraphQLListenAddrFlag,
-		utils.GraphQLPortFlag,
 		utils.GraphQLCORSDomainFlag,
 		utils.GraphQLVirtualHostsFlag,
 		utils.HTTPApiFlag,
@@ -350,18 +348,20 @@ func geth(ctx *cli.Context) error {
 	if args := ctx.Args(); len(args) > 0 {
 		return fmt.Errorf("invalid command: %q", args[0])
 	}
+
 	prepare(ctx)
-	node := makeFullNode(ctx)
-	defer node.Close()
-	startNode(ctx, node)
-	node.Wait()
+	stack, backend := makeFullNode(ctx)
+	defer stack.Close()
+
+	startNode(ctx, stack, backend)
+	stack.Wait()
 	return nil
 }
 
 // startNode boots up the system node and all registered protocols, after which
 // it unlocks any requested accounts, and starts the RPC/IPC interfaces and the
 // miner.
-func startNode(ctx *cli.Context, stack *node.Node) {
+func startNode(ctx *cli.Context, stack *node.Node, backend ethapi.Backend) {
 	debug.Memsize.Add("node", stack)
 
 	// Start up the node itself
@@ -381,25 +381,6 @@ func startNode(ctx *cli.Context, stack *node.Node) {
 	}
 	ethClient := ethclient.NewClient(rpcClient)
 
-	// Set contract backend for ethereum service if local node
-	// is serving LES requests.
-	if ctx.GlobalInt(utils.LegacyLightServFlag.Name) > 0 || ctx.GlobalInt(utils.LightServeFlag.Name) > 0 {
-		var ethService *eth.Ethereum
-		if err := stack.Service(&ethService); err != nil {
-			utils.Fatalf("Failed to retrieve ethereum service: %v", err)
-		}
-		ethService.SetContractBackend(ethClient)
-	}
-	// Set contract backend for les service if local node is
-	// running as a light client.
-	if ctx.GlobalString(utils.SyncModeFlag.Name) == "light" {
-		var lesService *les.LightEthereum
-		if err := stack.Service(&lesService); err != nil {
-			utils.Fatalf("Failed to retrieve light ethereum service: %v", err)
-		}
-		lesService.SetContractBackend(ethClient)
-	}
-
 	go func() {
 		// Open any wallets already attached
 		for _, wallet := range stack.AccountManager().Wallets() {
@@ -451,7 +432,7 @@ func startNode(ctx *cli.Context, stack *node.Node) {
 				if timestamp := time.Unix(int64(done.Latest.Time), 0); time.Since(timestamp) < 10*time.Minute {
 					log.Info("Synchronisation completed", "latestnum", done.Latest.Number, "latesthash", done.Latest.Hash(),
 						"age", common.PrettyAge(timestamp))
-					stack.Stop()
+					stack.Close()
 				}
 			}
 		}()
@@ -463,24 +444,24 @@ func startNode(ctx *cli.Context, stack *node.Node) {
 		if ctx.GlobalString(utils.SyncModeFlag.Name) == "light" {
 			utils.Fatalf("Light clients do not support mining")
 		}
-		var ethereum *eth.Ethereum
-		if err := stack.Service(&ethereum); err != nil {
+		ethBackend, ok := backend.(*eth.EthAPIBackend)
+		if !ok {
 			utils.Fatalf("Ethereum service not running: %v", err)
 		}
+
 		// Set the gas price to the limits from the CLI and start mining
 		gasprice := utils.GlobalBig(ctx, utils.MinerGasPriceFlag.Name)
 		if ctx.GlobalIsSet(utils.LegacyMinerGasPriceFlag.Name) && !ctx.GlobalIsSet(utils.MinerGasPriceFlag.Name) {
 			gasprice = utils.GlobalBig(ctx, utils.LegacyMinerGasPriceFlag.Name)
 		}
-		ethereum.TxPool().SetGasPrice(gasprice)
-
+		ethBackend.TxPool().SetGasPrice(gasprice)
+		// start mining
 		threads := ctx.GlobalInt(utils.MinerThreadsFlag.Name)
 		if ctx.GlobalIsSet(utils.LegacyMinerThreadsFlag.Name) && !ctx.GlobalIsSet(utils.MinerThreadsFlag.Name) {
 			threads = ctx.GlobalInt(utils.LegacyMinerThreadsFlag.Name)
 			log.Warn("The flag --minerthreads is deprecated and will be removed in the future, please use --miner.threads")
 		}
-
-		if err := ethereum.StartMining(threads); err != nil {
+		if err := ethBackend.StartMining(threads); err != nil {
 			utils.Fatalf("Failed to start mining: %v", err)
 		}
 	}

cmd/geth/usage.go

@@ -142,8 +142,6 @@ var AppHelpFlagGroups = []flags.FlagGroup{
 			utils.WSApiFlag,
 			utils.WSAllowedOriginsFlag,
 			utils.GraphQLEnabledFlag,
-			utils.GraphQLListenAddrFlag,
-			utils.GraphQLPortFlag,
 			utils.GraphQLCORSDomainFlag,
 			utils.GraphQLVirtualHostsFlag,
 			utils.RPCGlobalGasCap,
@@ -231,6 +229,8 @@ var AppHelpFlagGroups = []flags.FlagGroup{
 			utils.LegacyWSApiFlag,
 			utils.LegacyGpoBlocksFlag,
 			utils.LegacyGpoPercentileFlag,
+			utils.LegacyGraphQLListenAddrFlag,
+			utils.LegacyGraphQLPortFlag,
 		}, debug.DeprecatedFlags...),
 	},
 	{

cmd/p2psim/main.go

@@ -289,7 +289,7 @@ func createNode(ctx *cli.Context) error {
 		config.PrivateKey = privKey
 	}
 	if services := ctx.String("services"); services != "" {
-		config.Services = strings.Split(services, ",")
+		config.Lifecycles = strings.Split(services, ",")
 	}
 	node, err := client.CreateNode(config)
 	if err != nil {

cmd/utils/cmd.go

@@ -73,7 +73,7 @@ func StartNode(stack *node.Node) {
 		defer signal.Stop(sigc)
 		<-sigc
 		log.Info("Got interrupt, shutting down...")
-		go stack.Stop()
+		go stack.Close()
 		for i := 10; i > 0; i-- {
 			<-sigc
 			if i > 1 {